[15.] [308]

Anticipations of Rendu confirmed by Agassiz and Forbes; analogies with Liquid Motion established by Forbes; his Measurements in 1842; measurements in 1844 and 1846; Measurements of Agassiz and Wild in 1842, 1843, 1844, and 1845; Agassiz notices the "migration" of the Point of Swiftest Motion; true meaning of this observation; Summary of contributions on this part of the question

[16.]—Forbes's Theory. [311]

Discussions as to its meaning; Facts and Principles; definition of theory; Some Experiments on the Mer de Glace to test the Viscosity of the Ice

[17.]—The Crevasses. [315]

Caused by the Motion; Ice Sculpture; Fantastic Figures; beauty of the crevasses of the highest glaciers; Birth of a crevasse; Mechanical Origin; line of greatest strain; Marginal Crevasses; Transverse Crevasses; Longitudinal Crevasses; Bergschrunds; Influence of Flexure; why the Convex Sides of glaciers are most crevassed

[18.] [325]

Further considerations on Viscosity; Numerical Test; formation of crevasses opposed to viscosity

[19.]—Heat and Work. [328]

Connexion of Natural Forces; Equivalence of Heat and Work; heat produced by Mechanical Action; heat consumed in producing work; Chemical Attractions; Attraction of Gravitation; amount of heat which would be produced by the stoppage of the Earth in its Orbit; amount produced by the falling of the Earth into the Sun; shifting of Atoms; heat consumed in Molecular Work; Specific Heat; Latent Heat; 'friability' of ice near its melting point; Rotten Ice and softened Wax